Fluid-compressor.



G. WAINWRIGHT.

FLUID COMPRESSOR.

APPLIOATION FILED DBO. 20, 1911.

Patented Dec. 9, 1913.

3 SHEETfl-SHEBT 1.

WITNESSES: INVENTOR.

KM W1 (/MW W yl piyfi Arrokmw.

G. WAINWRIGHT.

FLUID COMPRESSOR.

APPLICATION FILED DEC. 20, 1911.

LQQLTYfi Patented Dec.9,1913.

3 SHEETS-SHEET 2.

WITIVES S- ATTORNEY.

G. WAINWRIGHT.

FLUID OOMPRESSOR.

APPLICATION FILED DEC. 20, 1911.

11,81,176 Patented Dec. 9, 1913.

3 SHEBTS-SHEET 3.

Q 1 VENTOR.

7 By M H ATTORNEY.

UNITED sTA'rEs PATENT omnoa.

CHARLES WAINWRIG-HT, OF ERIE, PENNSYLVANIA.

' YFLUID-COMPRESSORH acetate.

specification of Letters Patent.

Patented Dec. t), 191 3.

Application filedDecember 20, 1911. Serial No. 666,946.

.and useful Improvements in Fluiddlompressors, of which the following isa specification.

The general object of the invention is to improve or refine the mode ofunloading the cylinder of an air compressor as shown in my pendingapplication, Serial No. 646,349, filed AugustQSth, 1911.

In the above named application 1 provide a series of unloaders whichoperate successively at predetermined increasing pressures in thecontainer to close the intake chambers of the cylinders. With thisarrangement admirable results have been attained and especially withaltitude compressors,

but 1 have found and especially with the use of single stagecompressors, that a con.- siderable amount of negative work, due to thepistons compressing and expanding the air entrapped in the cylinder bythe closing of the intake, is thrown on the piston and consequently onthe motor as each unloader goes into operation. With the presentconstructionI overcome this defect by providing means adapted forpermitting the escape of air entrapped by the closing of the unloader;and further adapt this means to operate synchronously, or substantiallyso, with the unloader; and to this end the invention consists-in certainimproved constructions, arrangements, and combinationsof devices, whichwill be fully described hereinafter, and then pointed out in the claims.

Other objects will appear and be better understood from that embodimentof my. invention of which the following is a specification, referencebeing had to the accompanying drawings forming a part hereof, in which:

Figure 1 is a plan of a single stage air compressor which I select forone adaptation of my invention. Fig. 2 is aside elevation thereof. Fig.3 is an end elevation. Fig. 4 is a detail vertical cross section takenthrough one of the cylinders, unloaders and the intake box. Fig. 5 is adetail bottom plan of one of the cylinders. Fig. 6 is a detail verticalsection of one of the unloaders. Fig. 7 is a similar View of one of thesupplemental unloaders. Fig. 8 is a detail end elevation partly insection of the cylinder of an air compressor showing a modified form ofmy invention applied thereto. Fig. 9 is a detail, vertical section ofthe type of unloader shown in Fig. 8. Fig. 10 is a plan of a compressorprovided'with the modifica tion shown in Fig. 8. Fig. 11 is a side elevation of Fig. 10. Fig. 12 is an end elevation thereof.

In Figs. 1 to 3 inclusive, and 10 to 12 in elusive, a indicatesgenerally a motor which may be of any improved or desired constructionand of any preferred or desired. type i such as steam or electric, andsuitably adapted for operating the piston rod 6 to which are suitablysecured the pistons (not shown) which operate to compress the air in thecylindersf) and 6 of the fluid compressor which is herein shown to be ofthe single stage type and designated by c. 7

The base (i which supports the motor a is arranged beyond one end of theintake box 7 through the opening 8 of which the air or fluid to becompressed is drawn either from the atmosphere or other suitable sourceof supply. From the intake box 7 the air is drawn through the passages 9of the unloaders or choking controllers e which are arranged in pairs atthe opposite end portions of the intake box 7 and connected to theintake ports 10 and 11 which as shown in Figs. 4 and 5, are divided by awall 12 so that one of said chambers communicates with one end of thecylinder of which it forms a part, while the other chamber communicateswith the opposite end of the said cylinder. Suitable valves either ofthe puppet, or rotary type but not herein shown, are'arranged so as tocontrol the passages (not shown) between the intake ports 10 and 11 andthe 95 interior of the cylinders 5 and 6, these valves being operableeither mechanically or by the action .of the piston, all of which iswell. known and in use with various types of air compressors.

The air compressed in the cylinders may pass directly therefrom throughsuitable pipes 13-13 connected by a T 14, to the point where the air isto be used, or the air may pass through these pipes and T into 105 thecontainer (not shown). It being undeistood, of course, that there willbe provided suitable valves which will yield so as to admit air from thecylinders into the pipes and close under the pressure in the pipes.

By means of suitable pipes g communication is established between thecontainer or of closing haust passages 37 which is connected any othersuitable portion of the discharge system of the compressor and the inletopenings 15 of'the cylinders 16 of the unloaders e. The piston 17 ineach of the cylinders 16 is operated by the fluid pressure in the saidcylinder and moves against the action of a spring. 18,.the tension ofwhich is adjusted by an ad usting screw 19. Now, when the tension of thespring in each unloader is different from the tension of the springs inthe other unloaders, it will be manifest that the piston whose springtension is slightest will operate under less container pressure than thepistons of the other unloaders. When each of the pistons 17 is operatedas just described it lifts a needle valve 20 from its seat 21 throughwhich the container pressure passes into a chamber 22 and finally into acylinder 23 wherein a plunger 24; is located and adapted to be movedunder the action of the compressed air and against the action of aspring 25. The plunger, during its downward movement against the actionof the spring 25 lowers a valve 26 to its seat 2? in the passage 9. Thiswill have the effect the passage 9 and preventing the entrance of airinto that chamber of the cylinder with which the passage 9 communicates.Thus, the passage 9 will-be closed until the container pressure on' thepiston 16 is such as may be overcome by the spring 18. When this takesplace the spring 18 will move the piston 16 so that the needle valve 20will close the chamber 22 and the entrapped air in the chamber 22 willescape through a vent 28 in the pipe 29 which is suitably connected toan opening communicating with the chamber 22. As the air escapesthroughthe vent 28the spring 25 will operate to raise the piston 24 and openthe passage 9 by unseating the valve 26. i

As shown in Figs. 1 to 4 inclusive, the opposite ends of the cylinders 5and 6 have ex- 30 to each of which is suit-ably connected such as by anipple 31, one end of a passage 32 of a supplemental unloader f.The'passage 32' is suitably adapted to communicate with the source offluid supply for the compressor. In the present instance and merely toillustrate one application of my invent-ion, I cylinder connected bypipes 33 and 34 which are in turn connected to the exhaust passages 32ofv the unloaders f and tea T 35 to which is connected a pipe 36 whichis directed into the supply chamber 7 all of which is shown in Figs. to3 inclusive.

Each unloader f has an interior cylinder by the pipe '29 (frag ments ofwhich are shown in Figs. 1 to 3 inclusive and in Fig. 6), to the chamber22 of one of the unloaders e and the compressed air which is conveyedthrough the pipe 29 to the cylinder37 operates a piston 38 in the saidcylinder to which a valve 40 is suitably showthe unloaders f of eachconnected such as by means of a rod 39. In their normal-positions thevalve 40 is held to its seat 41 m'the passage 32, and the piston is heldto the lower end of the cylinder, as viewed in Fig. 7, by the action ofa spring 42 so that normally the valves 40 oh the unloaders f will cutoff communication between the exhaust passages 30 and the source offluid supply, or the chamber 7 In carrying out -the=principles=ofmy-invention the springs of the supplemental unloaders f are adj ustedbyany suitable means such as by nuts, one of which-is shown andindicated by 43, so that the tension of each spring of each supplementalunloader corresponds to the tension of the spring 16 bfthe unloader e towhich it is connected. In doin this I adapt each connected unloader andsupplemental unloadertoact in unison and under a predeterminedontainerpressure. In order to set forth the advantage gained by thiscombination of part'sand at the same time to give anunderstandingofl'thebroad principleof my invention regardless as to thetype of compressor to which it may be applied or the number ofunloadersand sup plemental unloaders used, the following is given :-In theembodiment-shown, four-hum loaders and four supplemental unloaders areemployed. Now let it be assumed thatthe unloaders on cylinder 6 areadjusted so as to operate at 90 and 93 pounds respectively and thesupplemental unloaders to which these unloaders are connected areadjusted the same predetermined The un-v so as to operate at pressures,viz., 90 and 93 pounds. loaders connected to the cylinder 5 areadrespectively, so also are the supplemental unloaders connected tothese last-named unloaders adjusted so as to stated pressures. Thus,when the container pressure it will be seen that is at 90 pounds thecompressed air from the container whicln enters the chamber 22 andcloses the valve 26, will also pass through the pipe 29 and into thecylinder 37 so that the valve 40 will be opened substantiallysynchronously with the closing of the valve 26. This will have theefiect of preventing the drawing of air through the chamber to which theunloader e is connected, but will permit of air being drawn through thepassage 32 and into the cylinder during the suction stroke. of thepiston thereof. But-the passage 32 is now open, and the air drawn mtothe cylinder, instead of bein compressed by the compression stroke of te piston therein, will be expelled through the passage 32. Thus, it willbe seen that the provision of the sup lemental unloaders will have theefiect of e imi'nating the negative work on the pistons after theclosing of the main unloaders.

this will be further manifest upon the closing of the second unloader,and still further justed so as to operate at 95 and 98 pounds operate atthe last the compression strokes of the pistons will be that of theatmosphere or the pressure in the chamber 7, and this under mostconditions is so relatively small as to require no notice.

In the modified form shown in Figs. 9

to 12 inclusive, the cylinders44 and 45 are connected by tubing 46-46.

The cylinders 44 and 45 are constructed similarly to the cylinders 5 and6, as shown in Figs. 4 and 5. Asshown in Figs. 8 and 11, however, theintake chamber 50 is connected by the tubing 4646 to the common inlet47. In this instance the inlet valve 51, which is of standardconstruction, also acts as an unloader or choln'ng controller or exhaustvalve. Each inlet valve 51 or the desired number on each end of acylinder, is controlled through the action of a plunger or piston 54in acylinder 55 which is connected by a pipe or tube 56 to the chamber 57 ina controller 9. A piston 58 located in a cylinder 59 formed with thecontroller carries a needle valve 60 which controls'com- .municationbetween the cylinder 59 and the chamber 57 and the pipe 61 whichconnects with the cylinder 59 and with the container (not shown) conveysthe compressed air from the container to the cylinder 59. The

'. spring 62 which bears upon the piston 58 pressure, it will bemanifest that when the several controllers are adjusted to operate atdiiferent predetermined container pressures the same result asheretofore pointed out with reference to the preferred :form, will beobtained as each end of the cylinder or cylinders are in their turnunloaded.

; In concl ision I may state that I do not intend to hunt myself to theuse of the parscribed. invention does not reside so much in theconstruction or particular op eration of any of the unloaders shown, asm the result obtained. In the preferred form by connecting the unloadersso that they will operate in unison or substantially so, the parts areconnected so that each unloader may control the operation of thatunloader ticular tylpfs of unloaders shown and deto which it isconnected; while in the modified form each unloader or inlet valve orvalves is operated directly by the container pressure. Moreover, and forthe reason that the rinciple of my invention'does not depend uponpneumatically operated unloaders it must be understood that I do notintend to limit myself to the use of liquid pressure for carrying outthe principle of my invention, since it will be manifest that thisprinciple may be carried out by the use of me-- chanically operatedunloaders which are now in use or by a combination of mechanically andpneumatically operated controllers.

What I claim as new is: a 1

1. In an air compressor, the combination of an intake box, a cylindersuperimposed on the box and having an intake port, a choking controllerinterposed between the' cylinder and the intake box and communicatingwith the intake of the cylinder, a relief devlce directed into one endof the cylinder and operatively connected to the choking controller.

2. In a double acting air compressor, the combination of an intake box,a cylinder superimposed upon the box and having spaced intake ports anda pair of choking controllers interposed between the cylinder and theintake box and communicating with the intakes of the cylinder, aplurality of re- CHARLES WAINWRIGHT.

Witnesses:

JAMES N. ALLBUnN, FRED J. CARNEY.

